It will be good if the libreOffice has translation feature like ms office. Sometime I want to see the translation of one word without need to go to firefox or other dictionary tools. It will be nice if it likes synonyms feature.

I'd like to add to this request with a little extension.
Wordreference.com offers a per-term translation of really good quality, but does not (to my kowledge) offer web services.
translate.google.com offers web services as well as a text block translation of arguably not excellent but acceptable basic translation.
The Google translator toolkit (http://translate.google.com/toolkit/list?hl=en#translations/active) is a bit better at that. It also allows you to send an entire document (in a series of formats including .odt) and supposedly translates it for you then gives it back to you.
However, that last feature breaks most of the style of any document you would submit to them.
When translating a long user/technical documentation (for open-source projects in particular because this is really missing in general terms), a first part of the translation time is spent on finding basic phrasing of what is written in the other language.
I personally think it would be great to have a feature to translate one paragraph at a time, using the translate.google.com API and maintaining basic formatting: alignments, bold, italic and specific styles applied (but excluding references, index markup, etc in a first version).
There are many extensions I can see developing on top of that later on, but that would be a first shot.
So the idea, in short would be, for the user:
* Configure a Google translate API (or any other translation API, but for simplicity I'm developing the following based on one specific provider)
* Configure (somewhere) the original language of the document
* Configure the language of the document as the destination translation (normal LibreOffice feature to set document language)
* Select a word or a whole paragraph
* Click-right and select "Translate through Google(TM)"
* The work or paragraph is changed, in-place, keeping all simple styling tags
On the back-end side, when the command is launched:
* Make sure the paragraph respects characters limitations, otherwise cut in chunks (preferrably on phrases separators) or ask the user to select a smaller part.
* Get the original document language
* Get the destination language
* Get the list of languages ("from" and "to") from Google and ensure there is a match between local language defined and Google language
* Send a call to translate.google.com 's API (http://code.google.com/apis/language/translate/overview.html) to translate the paragraph
* Replace the selected text by the translated version returned by Google, trying to maintain the style as much as possible
I have been translating documents for more than 120h in the last 45 days and I think it would really reduce my work of about 20% to have this kind of feature.
As such, I am ready to put a $200 bounty on the development of this feature (payable through PayPal). Check with me if this is still true if you take this over in a long time.

Dear bug submitter!
Due to the fact, that there are a lot of NEEDINFO bugs with no answer within the last six months, we close all of these bugs.
To keep this message short, more infos are available @ https://wiki.documentfoundation.org/QA/NeedinfoClosure#Statement
Thanks for understanding and hopefully updating your bug, so that everything is prepared for developers to fix your problem.
Yours!
Florian

Dear bug submitter!
Due to the fact, that there are a lot of NEEDINFO bugs with no answer within the last six months, we close all of these bugs.
To keep this message short, more infos are available @ https://wiki.documentfoundation.org/QA/NeedinfoClosure#Statement
Thanks for understanding and hopefully updating your bug, so that everything is prepared for developers to fix your problem.
Yours!
Florian

Dear bug submitter!
Due to the fact, that there are a lot of NEEDINFO bugs with no answer within the last six months, we close all of these bugs.
To keep this message short, more infos are available @ https://wiki.documentfoundation.org/QA/NeedinfoClosure#Statement
Thanks for understanding and hopefully updating your bug, so that everything is prepared for developers to fix your problem.
Yours!
Florian

Dear bug submitter!
Due to the fact, that there are a lot of NEEDINFO bugs with no answer within the last six months, we close all of these bugs.
To keep this message short, more infos are available @ https://wiki.documentfoundation.org/QA/NeedinfoClosure#Statement
Thanks for understanding and hopefully updating your bug, so that everything is prepared for developers to fix your problem.
Yours!
Florian